Lua Programming Help Thread

[Merick]

(You posted twice ^^)

I see that now, but I was in a hurry and right after I posted that my browser crapped out on me so I couldn't tell

[KleptoOne]

Something like this:

pad = Controls.read()
ax = pad:analogX()
if math.abs(ax) > 32 then
--Right
end
if math.abs(ax) <-32 then
--Left
end
ay = pad:analogY()
if math.abs(ay) > 32 then
--Up
end
if math.abs(ay) <-32 then
--Down
end

This code is flawed and I wish people would stop sharing it.
math.abs(ax) <-32 will never be true, math.abs() will return the absolute value of a number, so math.abs(-50) will equal 50.

[Bob Hoil]

Thanks guys i will go to the forums

[SuperBatXS]

This code is flawed and I wish people would stop sharing it.
math.abs(ax) <-32 will never be true, math.abs() will return the absolute value of a number, so math.abs(-50) will equal 50.

Wow, i really have to stop posting. At least i wasn't spamming (whew*). Anyways, thanks for pointing that out. :)

[KleptoOne]

Wow, i really have to stop posting. At least i wasn't spamming (whew*). Anyways, thanks for pointing that out. :)

By all means, post as much as you like, just make sure you know the code before you share it, because if you don't it can lead to 50 more questions.

[ahrimanes]

hy there people, is there a luaplayer mod thas includes:
System.setCpuSpeedVHigh() --Sets CPU to 333 Mhz
System.setCpuSpeedHigh() --Sets CPU to 300 Mhz
System.setCpuSpeedMed() --Sets CPU to 266 Mhz
System.setCpuSpeedReg() --Sets CPU to 222 Mhz
System.setCpuSpeedLow() --Sets CPU to 200 Mhz
System.setCpuSpeedVLow() --Sets CPU to 100 Mhz
and
Gum.lookAt
i see the lua player v0.20mod
it have the cpuspeed, but not the gum.lookat

[Anti-QuickJay]

That would be cools lua player mod 2

[ahrimanes]

That would be cools lua player mod 2

waaa thankss.. i found it thankss thanksss.. oo by the way. i read that in the mod 3 cools has remover the speed functions cos it myght me dangerous is that true ??? using the cloock speed could damage psp ?

[SuperBatXS]

waaa thankss.. i found it thankss thanksss.. oo by the way. i read that in the mod 3 cools has remover the speed functions cos it myght me dangerous is that true ??? using the cloock speed could damage psp ?

No. Overclocking does NOT damage the psp (well, it depends on how much you "overclock" it). I don't think that there is homebrew that overclocks above 333MHz (correct me if i am wrong; it can be done though?). Having the Cpu speed 333MHz is proven that Sony designed the psp to be like that. Overclocking the psp does NOT damage the psp (333MHz). However, it does reduce play time because it consumes quite a lot of battery.

[PSPJunkie_]

The PSP was meant to run at 333, Sony just had to compete with the battery life of Nintendo's DS. Technically, you really aren't overclocking since Sony underclocked it.

[Grimfate126]

Something like this:

pad = Controls.read()
ax = pad:analogX()
if math.abs(ax) > 32 then
--Right
end
if math.abs(ax) <-32 then
--Left
end
ay = pad:analogY()
if math.abs(ay) > 32 then
--Up
end
if math.abs(ay) <-32 then
--Down
end

rofl.

also, that is not the correct usage of the analog. you're using it as an alternative to the d-pad, which it should be. the analog is meant for pressure sensitivity. use it to your advantage.
-= Double Post =-

waaa thankss.. i found it thankss thanksss.. oo by the way. i read that in the mod 3 cools has remover the speed functions cos it myght me dangerous is that true ??? using the cloock speed could damage psp ?

there is a 30% chance of bricking when you overclock. JK!! (before i get banned)

to add on to the 2 peeps above me, overclocking is not dangerous, but it has two bad sides:

1. reduces your battery life. not sure how much, but i know its not a tiny bit
2. its a very cheap way to get better performance. people use to make up for their ghey optimization skills.

[ahrimanes]

well ok thanks every one. for this explanation, i think i will go trhowth the optimization way :P

[SG57]

Grimfate - FYI, the PSP is no Alienware, and although no PSP homebrew optimized to the fullest would require overclocking, its still a useful way to hlep your framerate along when your still a youngin' not knowing how to use C++ to the fullest (templates ftw)

[Urameshi]

how come this doesnt work, even though i thought it would:

function level4()
nbc=0
ncc=3
showblock=false
lol=true
	while true do
	screen:clear()
Enemy.x=40
Enemy.y=50
Stick.x=117
Stick.y=234
Stick2.x=230
Stick2.y=0
Square.x=480
Square.y=45

if collision(Player,Stick2) then
lol=true
else if collision(Player,Stick2) and Player.img == Sball then
lol=false
end
end

if lol then
dofile("br.lua")
end

if collision(Player,Square) then
Player.img = Sball
end

screen:blit(Stick2.x,Stick2.y,Stick2.img)

movePlayer()
screen:blit(0,0,lvl,true)
screen:blit(Player.x,Player.y,Player.img)
screen:blit(Enemy.x,Enemy.y,Enemy.img)
screen:blit(Stick.x,Stick.y,Stick.img)
screen:blit(Square.x,Square.y,Square.img)
screen.waitVblankStart()
screen.flip()
end
end

[w00tguy123]

This is my function for generating random cards and placing them into my hand (this function just generates the card though).

function drawcard1()

randz = math.random(1,6)

if randz == 1 then
hand1 = Image.load("cards/vector.png")
end 

if randz == 2 then
hand1 = Image.load("cards/marshie.png")
end 

if randz == 3 then
hand1 = Image.load("cards/ring.png")
end 

if randz == 4 then
hand1 = Image.load("cards/luigi.png")
end 

if randz == 5 then
hand1 = Image.load("cards/homsar.png")
end 

if randz == 6 then
hand1 = Image.load("cards/young_link.png")
end 
end

Is there anyway i can change it so that when a number is chosen it is never picked again? ( or until a new game is started )

-thanks in advance

[SG57]

wootguy -

-- Globally
used = {}
-- Place these 6 lines in your 'NewGame' function for when a new game is started
used[1] = false
used[2] = false
used[3] = false
used[4] = false
used[5] = false
used[6] = false

function drawcard1()

randz = math.random(1,6)

if randz == 1 and used[1] == false then
hand1 = Image.load("cards/vector.png")
end 

if randz == 2 and used[2] == false then
hand1 = Image.load("cards/marshie.png")
end 

if randz == 3 and used[3] == false then
hand1 = Image.load("cards/ring.png")
end 

if randz == 4 and used[4] == false then
hand1 = Image.load("cards/luigi.png")
end 

if randz == 5 and used[5] == false then
hand1 = Image.load("cards/homsar.png")
end 

if randz == 6 and used[6] == false then
hand1 = Image.load("cards/young_link.png")
end

used[randz] = true 
end

I believe that should work (Although im pretty out of it right now... 420 and all :P)

[xmex]

doesnt math.random return with decimal places? dont you need to math.round it or am I stuck in another programming language here.

[SG57]

No, Lua Player does it for you. (atleast thats how ive been using it)

[Merick]

math.random() by itself will return a number greater than 0 but less than 1, put one number in the brackets and it will return a number between 0 and that number, put two numbers in and it will return a number between the two numbers

[w00tguy123]

that seemed to work, but is there a way i can get more realistic random numbers? because every time i start the game, my first hand is always the same.

I know that "math.randomseed(os.time( ))" is supposed to give realistic random numbers, but i'm not sure how to use it.

[Merick]

ermm... you use it just like that....

[w00tguy123]

will it still give random numbers between 1 and 6? and it gives me the error "table index is nil"

[TacticalPenguin]

math.randomseed(os.time)

blah = math.random(1,6)

[w00tguy123]

so i put blah under "math.randomseed(os.time( ))"?

[TacticalPenguin]

Dude, if you cant figure that out, please, stop programming.
And yes, you do.

[w00tguy123]

well the reason i asked was because it wasn't working, but now i know that it's from something else

[SG57]

TP - Its a help forum, he's new, and not everyone knows it must be called only once from the start of hte program, so lay off. So cranky...

Wootguy - Place it at the start of your script (AKA not in your infinite loop)

[w00tguy123]

thanks.

I also have one last question before I'm done here:
what does "table index is nil"" mean? The "index" part kinda threw me off.

[ahrimanes]

i hate when peole is like knowit all... poor people. they are lonly.
well i wass testing somthing whith oop, and got this to work:

--ahrimanes oop starfield
--usb active
System.usbDiskModeActivate()
--crear un nuevo objeto de color

gris1 = Color.new(100,100,100)
gris2 = Color.new(150,150,150)
gris3 = Color.new(200,200,200)
blanco = Color.new(255,255,255)

maxstars = 200
width = 480-1
height = 272-1
timer = 0
bf = Image.createEmpty(480, 272)
clsstar = {}
metastar = {}
math.randomseed(os.time())
function drawRect(x, y, width, height, color, w)
	w:drawLine(x, y, x+width, y, color)
	w:drawLine(x, y, x, y+height, color)
	w:drawLine(x+width, y, x+width, y+height, color)
	w:drawLine(x, y+height, x+width, y+height, color)
end
function clsstar:New() 
	x = math.random(width)
	y = math.random(height)
	z = math.random(3)
	if z == 1 then
		colora = gris1
		colorb = gris1
	end
	if z == 2 then
		colora = gris2
		colorb = gris2
	end
	if z == 3 then
		colora = gris3
		colorb = gris3
	end
	return(setmetatable({Position = {X = x, Y = y, Z = z},colora = colora,colorb = colorb}, metastar))
end 
function clsstar:draw() 
	screen:pixel(self.Position.X,self.Position.Y,self.colora)
	drawRect(self.Position.X-(self.Position.Z-1)/2,self.Position.Y-(self.Position.Z-1)/2,self.Position.Z-1,self.Position.Z-1,self.colora,screen)
	self.Position.Y = self.Position.Y + self.Position.Z * 2
	if self.Position.Y > height then
		self.Position.Y = 0
		self.Position.X = math.random(width)
	end
end 
metastar.__index = clsstar 
starfield = {} 
for i = 1, maxstars do
	starfield[i] = clsstar:New()    
end
while true do
	screen:waitVblankStart()	
	screen:clear()
	for i = 1, table.getn(starfield) do starfield[i]:draw() end
	screen:flip()
	
	pad = Controls.read()
	if pad:start() then
		break
	end
end

ok that work good, but im trayingo somthing else and wont work-

hero = {}
metahero = {}
function hero:new() 
	x = 480/2
	y = 272/2
	dx = 0
	dy = 0
	angle = 0
	oldangle = 0
	speed = 0
	return(setmetatable({X = x, Y = y, dX = dx, dY = dy, Angle = angle, Oldangle = oldangle, Speed = speed}, metahero))
end 
function hero:updt()
	pad = Controls.read()
	self.dX = pad:analogX()
	self.dY = pad:analogY()
	screen:print(0,0,self.dX,white)
	screen:print(0,20,self.dY,white)
	screen:print(0,30,self.X,white)
	screen:print(0,40,self.Y,white)
end

sooo
ship = hero:new()
then in mainloop
ship.updt()
and i got nil value on this line
screenrint(0,30,self.X,white)
whats worng?
itseems that the new obj hass all his fields nil wy ?

[KleptoOne]

well at a quick glance, the updt function is called from the hero table, which is where all your classes are stored, but your actual x, y, ect values are stored in the meta hero obj, so when you use self it is accessing the hero template which is the wrong one. I could be wrong though.

*Edit* After reading the first code set, I see that it uses the same structure. The only difference that I'm going to have to research to understand is this command:

metastar.__index = clsstar

Maybe that links the two objects in some way, I'm not sure, but if you can explain it that would be great. I never considered using OOP in lua, as the only reason I code in it is because tables are so easy to manipulate. Plus without true pointers, In my mind, it would be hard to keep your objects truely seperate.